Is this “iPhone 5″ screen protector a harbinger of new iPhone design?

A new screen protector that is supposedly for the iPhone 5 matches previous …

A purported screen protector for the iPhone 5 mirrors a number of early "leaked" case designs that suggested a significantly altered form factor for the upcoming device. While it could be a sign that Apple has something completely new in store for its next-gen iPhone hardware, case designs in the past have been hit or miss when it comes to predicting what new Apple hardware will look like.

There have been two competing rumors concerning the design of the iPhone 5. One posits that the external design will be very similar to the still popular iPhone 4, with the external antenna, 3.5" screen, and glass front and back. The other suggests something "radically" different, more akin to the current iPad 2, with a tapered aluminum back. This rumor has also suggested that the device will feature a larger, edge-to-edge screen—roughly 4"—and a revised, elongated home button.

Several case designs allegedly leaked out of China support the latter rumor, a radically changed design. A new screen protector revealed by Unwire.hk this week, designed to fit the front of the device, also supports a changed iPhone 5. When compared to an iPhone 4, it suggests the upcoming device will be even larger in width and height. It makes sense to a degree—if Apple plans to flatten the device, it would definitely want to increase the other dimensions to make enough room for a sizable battery.

However, as MacRumors notes, all of these early cases are designed around the same leaked design document, the authenticity of which has not been verified. Additionally, early case designs have a spotty track record of accurately foreshadowing new Apple devices. For instance, cases were made for a supposed iPhone "nano" that still has yet to materialize. And early cases for the third-gen iPod touch suggested it would get a rear-facing camera, but that didn't happen until the fourth-gen device was launched. On the other hand, early cases did reveal the design of the iPhone 3G and that the sixth-generation iPod nano would get a camera.

What little evidence there is so far leads us to believe the iPhone 5 will be a more conservative update on the outside, but with some improved internals. There's still a chance that a revised iPhone 4 will become an entry-level model and this other purported design will serve as an upscale new model, but we're not willing to make bets based on a case or screen protector.